Background : Current massive transfusion guidelines are derived from washout equations that may not apply to bleeding trauma patients. Our aim was to analyze these guidelines using a computer simulation.
Methods : A combined hemodilution and hemodynamic model of an exsanguinating patient was developed to calculate the changes in prothrombin time (PT), fibrinogen, and platelets with bleeding. The model was calibrated to data from 44 patients. Time intervals to subhemostatic values of each coagulation test were calculated for a range of replacement options.
Results : Prolongation of PT is the sentinel event of dilutional coagulopathy and occurs early in the operation. The key to preventing coagulopathy is plasma infusion before PT becomes subhemostatic. The optimal replacement ratios were 2:3 for plasma and 8:10 for platelets. Concurrent transfusion of plasma with blood is another effective strategy for minimizing coagulopathy.
Conclusion : Existing protocols underestimate the dilution of clotting factors in severely bleeding patients. The model presents an innovative approach to optimizing component replacement in exsanguinating hemorrhage.
From the Trauma Modeling Center, Ben Taub General Hospital (A.H., B.G.S., M.J.W., K.L.M.), and the Departments of Surgery (A.H., B.G.S., M.J.W., K.L.M.), Anesthesiology (M.D.), and Pathology (E.I.B.), Baylor College of Medicine, Houston, Texas.
Submitted for publication October 9, 2002.
Accepted for publication December 5, 2002.
Presented at the 61st Annual Meeting of the American Association for the Surgery of Trauma, September 26–28, 2002, Orlando, Florida.
Address for reprints: Asher Hirshberg, MD, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030; email: firstname.lastname@example.org.